1. Field of the Invention
The present invention relates to a thyristor having internal current gain wherein the thyristor comprises an n-emitter which carries a cathode, a p-emitter which carries an anode, and two base layers therebetween and respectively adjacent thereto, and to a method for operation of the thyristor.
2. Description of the Prior Art
A thyristor of the general type set forth above is known from the "Thyristor Handbook" by A. Hoffmann and K. Stokker, Verlag Siemens AG, Berlin and Munich, 1965, pp. 27-28. An interstitial auxiliary emitter is provided and is permeated by a current when the thyristor is triggered, which effects a rapid and large-surface ignition in the area of the principal emitter. Because of the rapid sequence of the entire trigger operation, a thyristor of this type is suitable for rapid rises of the load current flowing between the anode and cathode, i.e. it exhibits a high di/dt stability.
A thyristor having internal current gain is disclosed in the German patent application No. P 29 45 347.2 in which the principal emitter comprises a plurality of fixed emitter short circuits, whereas the auxiliary emitter is provided with emitter short circuits which can be optionally switched on by field effect transistor (FET) structures, i.e. are controllable. When it is switched on, then the thyristor exhibits good stability, i.e. high protection against unintentional trigger operations given the occurrence of voltages poled in the forward conducting direction which, under certain conditions, can rise very quickly, i.e. represent a high dU/dt load. On the other hand, the thyristor is trigger-insensitive given short circuits which are switched off.